Distribution valve



NOV. 4 1924.

A. E. CAMERON DISTRIBUTION VALVE Filed April 18, 1922 2 Sheets-Sheet l L fame/alt NOV. 4 v

A. E. CAMERON DISTRIBUTION VALVE Filed April 18, 1922 2 S heet-Sheet 2v Patented Nov. 4, 1924.

barren srnrss PATENT 4orricr. I

ALEXANDER n. CAMERON, orrnovinnlvon, nnonnfisnn vn, Assmma mism- GANSETT ELECTRIC LIGHTING COMPANY, or PROVIDENCE, ni-ronn IsL'AIvn'A con- ]?ORATION OF R-HOIDE ISLAND.

DiS'l'RIBUTiON 'VALVE.

Applicatiomfiled April 18,1922. Serial No. 554,'799.

To all whom it may concern:

Be it known that I, ALEXANDER E. 'CAMERON, a citizen of the United States, residing at Providence, in the county'of Providence and State of Rhode Island,-have invented new and useful Improvementsjin Distribution Valves, of which the follow ing is a specification.

This invention relates to distribution valves for boilers or other pressure vessels,

or objects of liquid supply, and has forits object the provision of means for controlling the simultaneous feeding of water or other liquids to each of'the several liquid chambers of a boiler or pressure vessel of the type having several evaporating units or drums, or for supplying water or other liquids at separate points to a single evaporating chamber such as is present a crossdrum boiler.

The'principal object of the invention is several drums of an equal supply of'water or other liquid.

Another object of the invention is the construction of a distribution valve in a steam generating system of the type above described, in which the distributing ports are overned by the action of a differential piston, the'top side being connected to the boiler drum below waterline, or'to one oil the conduits itself, so as to maintain a pressure as nearly equal as possible to that in the boiler, and to take care of any leakage that passes by the piston. The excess area exposed ontop of thepiston, togethcrwith the weightof same, tend to keep the valve shut, which weight and holdingdown effort are determinative of the pres sure head of the water entering into the boiler through said delivery conduits.

A further object of the invention is the provision of distributing ports in the distributionvalve, which a're' v'shaped, having the apexof theV directed-downward and slightly uncovered by the piston when inits lowermostposition, by which "arrangement a very accurate range' can bemaintained in the'manner of"fiow,' froin small amounts tofull capacity. Bystarting o'tf right at the source with identical pressure" and orifice conditions which this'pistoir effects, in uncovering the" V-ports, a decided advantage lsattained bythe increased velocity and pressure conditions atentran'ce' to conduits to overcome the "present difiiculties I of checks, and minor difficulties which'h'ere v tofore retarded equal flow of ater-and chose the paths of least resistance. I

With the above and other obj ects in'view, my invention consists in the improved' dis tribution valve illustrated in the'ac'coinpanying drawings, described in the following specification, and particularly claimed, and in such variations and modifications thereof as'will be obvious to those skilled'inthe art to which my invention relates.

' Inthe drawings accompanyingandforming a part of thisspecification, and-wherein the preferred embodiment of my invention is illustrated:

Figure l'is a view, largelyjdiagrammatic showing a steam generating system in which .myimproved distribution valve is in'terc'alated. I W Figure 2 1s a crosssection'al viewin eleva-,

tion ofthe distribution valve the distributin aortsbein substantiall closed.

Pa D

Figure 3 is a cross sectional elevation taken at right angles to the view shownin Figure 2, with the distribution ports open. Fi ure 4 1s a view incrosssection taken along the line 44 ofFigure 2. I

Referring now in letail to the several figures the numerals 1,2,and 3'denote'respectively the three evaporating" chambers or drums ofa tl1ree drumbo1ler. These chambers are connected at their lower, rear banks of tubes36 by a common mud drum 4' which equalizes the waterleveli'n the, different drums by being in communication with each other. "The upper portion of'each of said'drums is 'connected to the common steam deliverypipe37 so that the steam pressure in 'each'ofsaid drums is substantially equal. v r

The water spaces within the drums 1, 2

v itiaeio and 3 are in communication with individual conduits 5 6 and 7 respectively by means of which water is fed to said drums from the water main 8 through the agency of the manually operable supply valve 9 and the automatic distribution valve 10 which constitutes the subject matter of this invention. A check valve 11 is in the lower end of each of said conduits 5, 6 and 7 adjacent the several drums the function of which is to prevent the forcing out of the water from said drums by the pressure'of steam above the water level therein.

In the ordinary boiler of the plural drum type, as here illustrated or in boilers having a single drum with provision for introducing water thereinto at a plurality of separate points, much difficulty has been encountered in securing equal distribution of feed water to all the points of admission to said drums. This is due to the factthat the conduits leading to the points of delivery may become more or less choked or coated with sedimentary or other deposits, thus roughening the inner surfaces of said conduits and producing an excessive friction between the walls of said conduits and the column of water flowing therethrough, decreasing the velocity of the latter. It is a common experience also to find that the check valves open with unequal freedom due 1 to stickiness, and other causes, thus opposing an unequal resistance to the water flowing through each of said conduits. In

the absence of a distribution valve, such as is embodied in this invention, for corre cting the unequal distribution of feed water, the pressure at which said water enters the boilers will be so slightly in excess of the boiler pressure that the unequal resistances opposed to the flow of said feed water through said conduits, due to the 7 causes aforementioned, are so proportionately large, to the pressure of the feed water that it materially retards the flow of water through those conduits in which the back pressure is relatively great. This results in the feeding in of unequal amount of water to the several drums during the time that the supply valve 9 is open.

This is attended by the following objectionable result. The temperature of the feed water is necessarily considerably below the temperature of the water in the drums, therefore, that drum which receives the greatest amount of water during the time feed water is being supplied to the set of drums, will have the temperature of its liquid contentsso reduced that there will be a temporary falling off in the rate of evaporation in said section of boiler, while the water in the drum receiving the least quantity of feed water will not be chilled to the same extent, the rate of evaporation remaining relatively high. In consequence the tubes under the latter drum will be compelled to. do more than their share of work of generating steam. particularly in a system which is provided with automatic means for maintaining a constant. steam pressure, in which case said tubes will be foced to generate the greatest percentage of steam for the entire boiler until the term per-ature of the water in the other drums become elevated to the normal working temperature of the system. In a short time the tubes of this section will be covered with an excessive deposit of scale necessitating their frequent replacement.

The present invention aims to correct this defect by insuring the supplying of equal amounts of water to each of the drums in the same time, and thereby producing a uniform fall of temperature in each of said drums so that the tubes of each unit share equally in the generation of steam required of said boiler. This is done by increasing the velocity of flowof the feed water through each of the individual conduit 5, 6 and 'T so.

that the unequal back pressures are so relatively small compared with the pressure by which the feed water is impelled into the drums, that it becomes negligible as a factor in reducing the velocity of flow of water through said conduits. The velocity being substantially constant, equal amounts water will be distributed to each drum in the sametime, that is to say while water is being fed to the distribution valve by the supply valve 9. I

The distribution valve by which this desirable result is accomplished comprises a casing 18 which is preferably cylindrical in form and closed at the top by a head 14 flanged upper end 16 of saidcasing. The

bottom of said casing is similarly flanged as at 17 to which is secured the end plate 18 which carries a downwardly extending yoke 19. Arranged peripherally about an intermediate portion of the casing 13 are the flanged outlets 20 which are similar in number to the drums which are to be supplied with feed water and are connected thereto by means of the conduits 5, 6 and 7 shown in Figure 1 and indicated in dotted lines in Figures 2 and 3. Said flanged outlets are provided with ports which are circular at their outer ends and V shaped as shown at 21 where they communicate with the bore of the cylindrical casing, the apices of said ports being directed downwardly, said ports diverging in an upward direction.

The bore within the cylindrical casing 13 is of two diameters, that, portion with which the outlets communicate being of slightly smaller diameter than the portion above said outlets. A differential piston 22 traverses the bore of the casing 13 and is of two diameters corresponding to the diameters of the emme bore within said casing. Said piston makes a sealing lit with the interior walls of the casing 13 and when in its low position substantially closes the t -shaped ports, leaving but a minute portion adjacent the apices o'l' said ports open to communication with the conduits 5, 6 and 7. The extent of upward movement of said piston is limited by a pro jecting stem 23 secured to the upper face 82 of said piston and adapted to make engagement with the inner wall of the head 14. When the piston is in uppermost position, the ports 21 are wide open, and between the upper and lower limits of travel of said piston said ports are more or less open accordingly. The space within the casing 13 above said piston is in communication with one of the individual conduits leading to the several drums, being connected in the present instance to the middle conduit 6 by the pipe 25 which makes connection with said casing 18 through a threaded aperture 26 in the wall thereof. A piston rod 27 extends below the lower face of the piston to the end of which a guide member 29 is secured, being provided with radial arms 30 as shown in Figure l which travel closely adjacent the walls of the cylindrical bore ot the casing and prevent the piston from being cramped or diverted from an axial path of travel. The guide 29 is indented between said radial arms forming a passageway for the inflow of teed water admitted to the casing 13 by means of the flanged inlet 31 which is connected to the source 8 of water supply. The water in said source oi? supply is maintained at a pressure in excess of the steam pressure within the boiler. The area of the upper face 32 of the piston slightly exceeds that of the lower face 83 so that the pressure upon said upper face communicated to it from the conduit 6 through the pipe 25 is about two pounds in excess or the water pressure against the lower surface of said piston when the ports 21 are subjected to the pressure in the boiler, as happens when the check valves are raised by the pressure of the teed water. This slight excess pressure plus the weight of the piston, which may amount to about two pounds more, is exerted upon the teed water, preventing the opening of the ports 21 until the teed water has assumed a pressure about four pounds in excess of the boiler pressure, thereb increasing the velocity of the feed water through the conduits 5, 6 and 7 to such an extentas to render negligible and immaterial the slight unequal back pressure created by untoward conditions within said conduits such, as'have been hereinhetore assumed.

The oywration oi? my improved distribution valve is follows. Withthe parts oil? the system arranged as shown in Figure l, and with the piston in its normal depressed position in which the ports 21 are almost closed it is desired to admit feed water to the several drums. of the supply valve 9 is partially opened, water flows from the water supply main 8 through the flanged inlet 31 into the cylindrical valve chamber below said piston.

At this time the upper face of the piston is subjected to water pressure equal to the pressure in the boile communicated to 'it by the conduit 25 as will be observed from Figure 2. The lower edge of the piston when in its lowermost position barely clears the lower edge of the portsfQl, so that the latter are open to a very slight degree permitting the feed water to act directly against the check valves 11, which are under boiler pressure. As soon as the. pressure of teed water within said conduit is suilicient to open the check valves the pressure against the lower face 33 of the piston will be equal, per unit of area to the pressure within the boiler. l/V ere the piston not present, as in ordinary systems of distribu tion the feed water, would slowly flow into the several drums past the check valves at a pressure slightly in excess oi the boiler pressure, and consequently at a very low velocity, so that any inequality in the resistance opposed to said flow in said. conduits would have a retardative effect upon the velocity in the conduit opposing the greatest obstruction to the flow of the teed water therethrough, so that during the time the supply valve 9 is open, unequal amounts or" water will have been supplied to the several drums. Butthe pressure upon the upper face 32 of the piston, due to itslarger area, plus the weight of said piston will prevent further opening of said ports 21, until the pressure of the feed water-below said piston has increased sufficiently to overcome the excess pressure of said piston, whereupon the latter will be raised admitting equal flow ot water to each drum. This tlow being under a pressure of about four pounds in excess of boiler pressure will be of considerably higher velocity than it would be in th absence of the piston, the

unequal back pressure in any of said conduits being a, negligible factor compared with, the pressure of the intlowing water. Thus equal volumes of water will be admitted in the same time to each of the drums, and the reduction in temperature in each of said drums incident to the entrance of the feed water thereinto will be substantially the same, consequently each of the evaporating units will perform the same amount of work and no single set of tubes will be overworked in the attempt to keep up steam output in the boiler;

The fundamental difference between this method of insuring equal feed to the pressure vessel and those previously obtained,

The hand wheel lies in the fact that provision is here made in a single cylinder or housing for receiver pressure on one side of the piston, and initial or pump pressure on the other side, thus insuring, with ports of equal area, the same differential driving pressure on the liquid through every port regardless of their number or extent of opening. in the other forms of feed, while initial pressure was frequently common to all ports, the drop in resistance of the pipe or conduit between receiver vessel and the port was also varied by the amount of opening in the port itself; all of these factors conspiring to produce unequal feed thru -if", ferent conduits.

Another advantage accruing to a steam g aerating unit of the type described in the use of the improved distribution valve, is that with equal firing conditions in the furnace and water supplied equally to the drums the conditions within the mud drum would be more favorable to bring about the desired results; namely the absence of circulation within the same, thereby depositing more scale forming material in a position ready to be blown out when the boiler is blown down, than if the water within the mud drum was in a state of constant turmoil of cross currents of water trying to equalize the level. up in the drums due to the unequal distribution of feed water. These cross currents within the mud drum also encounter the currents due to natural circulation descending the rear end of boiler and retard the latter to a considerable degree, thereby preventing the depositing of scale forming material at the desired point.

The V-shaped opening of the ports permits only a minute portion of the area of said ports to be normally uncovered when the piston is in its lowermost position, but

not sufficiently to supply a material quantity of water to the drums before the pressure of said feed water has overcome the downward pressure of the differential piston. This insures a gentle opening of the check valves as they are in direct communication with the feed water and will be lifted from their seats when the pressure of said feed water begins to exceed the pressure of steam in the boiler., The rapidly widening area of said ports as the piston rises insures that the desired quantity of water will be rapidly supplied to the drums,

The end plate 18 is centrally apertured and a rod 84-, constituting the stem of a hand wheel 35 projects through said aperture into contact with the lower end of the-piston rod 27. The rod 34 makes threaded engagement with an apertured portion 36 of the yoke 19 so that by turning'the hand wheel in one or the other direction the rod 35 may be advanced into contact with the piston rod 27 to raise said piston, or retracted so as to leave said piston free to perform its automatic operation. It is sometimes desirable to hold the piston open as when flooding the boilers, and the hand wheel 35 with its associated mechanism permits the piston to be held in an elevated'positio-n so as to maintain any degree of port opening that may be desired.

Having described my invention what I claim as new and desire to secure by Letters Patent, is

1. In a steam generating system comprising a plural drum boiler, a feed water conduit communicating with each drum, a source of water under pressure adapted to supply water to said drums through said conduits against the pressure of steam insa-id boiler, and means for-imposing apressure load upon said water additional to the pressure derived at said source, and in excessof the steam pressure of the boiler for increasing the velocity of flow thereof through said conduits.

2. In a steam generating system, a boiler, a plurality of feed water conduits connected thereto at separated points, a source of water under pressure adapted to supply feed water to said boiler through each conduit against the pressure of steam in said boil-er, and means between said source and said conduits t'or imposing pressure upon said water in addition to the pressure derived at said source and in excess of the steam pressure of said boiler, for increasing the velocity of flow thereof through said conduits.

8. In a steam generating system, a boiler, a plurality of feed water conduits connected thereto at separated points, a source of water under pressure, adapted to supply feed water to said boiler through each conduit against the pressure of steam in said boiler, and means subjected to boiler pressure for imposing pressure upon said water in excess of the steam pressure of said boiler for increasing the velocity of flow thereof through said conduits. 1

4-. In a steam generating system, a boiler, a plurality of feed water conduits connected thereto at separated points, a source of water under pressure, adapted to supply feed water to said boiler through each conduit against the pressure of steam in said boiler, and weighted means subjected to boiler pressure for imposing pressure upon said water in excess of the steam pressure of said boiler for increasing the velocity of flow thereof through said conduits.

5. In a steam generating system, a boiler, a plurality of feed water conduits connected thereto at separated points, a source of water under pressure adapted to supply feed water conduits connected thereto at separated points, a source of water under pressure adapted to supply feed water tosaid boiler through each conduit against the pressure of steam in said boiler, and means comtwi prisingl v a differential piston subjected to boiler pressure on both sides thereof for imposing pressure upon said water in excess of the steam pressure in said boiler, for increasing the velocity oi? flow thereof through said conduits.

6. In a steam generating ystem, a boiler, a plurality of feed water conduits connected thereto at separated points, a source of water under pressure adapted to supply feed water to said boiler through each conduit against the pressure of steam in said boiler, and a distribution valve in said system comprising a casing having a cylindrical bore, a piston slidable in said here, said casing being provided on one side of said piston with an inlet connected to said source and with outlet ports normally substantially closed by said piston but communicable with said inlet when the piston is elevated, said outlet ports being in communication with said conduits, a pressure connection from said boiler to said casing on the other side of said piston, and means for admitting water from said source to said casing to lift said piston.

7. In a steam generating system, a boiler, a plurality of feed water conduits con,- nected thereto at separate points, asource 01'- water under pressure adapted to supply feed water to said boiler through eachconduit against the pressure of steam in said boiler, a distribution va ve in said system comprising a casing having a bore, a piston slidable in said bore, said casing being provided on one side of said piston with an inlet connected to said source, and with l-shaped outlet ports normally substantially closed by said piston but communicable with said inlet when the piston is elevated, said outlet ports being in communication with said conduits, a pressure connection from said boiler-" to said casing on the other side of said piston and means admitting water from said source to said casing to lift said piston.

EL In a steam generating system, a boiler, a plurality of feed water conduits connected thereto at separated points, a source of water under pressure adapted to supply "feed water to said boiler "through each conduit against the pressure of steam in said boileiya distribution valve in said system comprising a casing having a boreot two diameters, a differential piston slidable in said bore, and having portions of two diameters fitting the diameters of said bore, said casing being provided on the smaller side of said piston with an inlet connected to said source and with outlet ports nor mally substantially closed by said piston but communicable with said inlet when the piston is elevated, said outlet ports being in communication with said conduits, a pressure connection from said boiler to said casing on the side of said piston. of larger diameter and means for admitting water from said source to said casing to elevate said piston.

twodiameters fitting the diameters of said bore, a stem projecting from the sideoit said piston of larger diameter and engaging said head when said pistonis in uppermost position, said casing being provided, in that portion of smaller diameterwith an inlet connected to said'sourceand with outlet ports normally substantially closed by said piston but communicable with said inlet when the piston is elevated, said out let ports being in communicationwith said conduits, a pressure connection from one of said conduits to saideasing-on the side 01' said piston of larger diameter, and means for admitting water trom said source to said casing to lift said piston.

10. In a steam generatingsystem, a boiler; a plurality of feed water conduits connected thereto at separated points, a' source of water under pressure adapted to supply feed water to said boiler through each con duit' against the pressure of steam insaid boiler, a distribution valve in said system comprising a casing having a bore of two diameters, a head for closing the upper end of said casing, a piston having portions of two diameters fitting the diameters of said here, a stem projecting from the side or said piston of larger diameterandengaging said head when said pistonis in uppermost position, said casing beingprovided, in that portion of smaller diameter with an inlet connected to said source and with outlet ports normally substantially closed by said piston but communicable :with said inlet when the piston is elevated, saidoutlet ports being in communication withsaid conduits a pressure connection from one of said conduits to said casing on the side ofsaid piston of larger diameter, means for admitting water from said source to said casing to lift said piston, and manual means for adjustably raising said piston to open said ports.

llLIn a steam generating system, a boiler, a plurality of feed water conduits connected thereto at separated points, a a source of water under pressure adapted to supply feed water to said boiler through said conduit against the pressure of steam of two diameters, a head closing the upper end of said casing, a piston having portions of two diameters to fit the diameters of said bore, said piston being slidable in said bore, a stem projecting from that side of the piston of larger diameter and engageable with said head when the piston is in its uppermost position, said casing being provided in that portion of smaller diameter with an inlet connected to said source, and with outlet ports normally substantially closed by said piston but communicable with said inlet when the piston is elevated, said outlet ports being in communication with said conduits, a pressure connection from one of said conduits to that portion of said casing of larger diameter, means for admitting water from said source to said casing to lift said piston, an end plate for the lower end of said casing, a yoke on said end plate having a threaded aperture, a stem slidably arranged through said end plate and engageable with said piston, said stem having a threaded portion engaging said threaded aperture and a hand wheel on said stem for operating the latter.

12. In a steam generating system, a boiler, a plurality of feed water conduits connected thereto at separated points, a source of water under pressure adapted to supply feed water to said boiler through said conduits against the pressure of steam in said boiler, a distribution valve in said system comprising a casing having a bore of two diameters, a head closing the upper end of said casing, a piston having portions of two diameters to fit the diameters of said bore,

said piston being slidable in said bore, a stem projecting from that side of the piston of larger diameter and engageable with said head when the piston is in its uppermost position, said casing being provided in that portion of smaller diameter with an inlet connected to said source, and with outlet ports normally substantially closed by said piston but communicable with said inlet when the piston is elevated, said outlet ports being in communication with said conduits, a pressure connection from one of said conduits to that portion of said casing of larger diameter, means for admitting water from said source to said casing to lift said piston, and end plate for the lower end of said casing, a piston rod projecting from the lower side of said piston, and

terminating within said casing, a yoke on said end plate having a threaded aperture, a stem slidably arranged through said end plate and engageable with said piston rod, said stem, having a threaded portion engaging said threaded aperture and a hand wheel on said stem for operating the latter.

13. In a steam generating system, a boiler, a plurality of feed water conduits connected thereto at separated points, check valves in said conduits opening to ard said boiler, a source of water under pressure adapted to supply feed water to said boiler through each conduit against the pressure of'steam in said boiler, a distribution valve in said system comprising a casing having a bore of two diameters, a head for closing the upper end of said casing, a piston having portions of two diameters fitting the diameters of said bores, said casing being provided, in that portion of smaller diameter with an inlet connected to said source and with V-shaped outlet ports having the apices thereof pointing downward, said piston in its lowermost position substantially closing said ports but leaving said apices uncovered said outlet ports being in communication with said conduits, a pressure connection from said boiler to said casing on the side of said piston of larger diameter, and means for admitting water from said source to said casing to unseat the check valves at a pressure substantially in excess of boiler pressure and to lift said piston to uncover substantial areas of said ports at a pressure in excess of said check-valve-opening pressure.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

ALEXANDER E. CAMERON. 

